MOLECULAR BIOLOGICAL STUDY ON THE MECHANISM OF LIGHTINDUCED DWARFISM (LIGHT-INDUCED GENE EXPRESSION IN DWARF PEA PLANTS)

为了阐明光诱导豌豆矮化的机理，采用差异显示的方法，对矮秆豌豆植株中与矮秆相关的特异基因进行了寻找。从矮生豌豆(Pisum sativum L.cv.)进展编号9)和普通豌豆(同上阿拉斯加)幼苗和两个品种的湿生幼苗。将Poly(A)^+RNA反转录后，利用72种随机引物，采用差异显示法对特异基因进行鉴定。共鉴定出20条差异表达条带，其中7条用于进一步鉴定。将这7条带克隆到载体上，测定其核苷酸序列，并在GenBank中搜索其同源性。以克隆的编码序列为探针，对克隆进行了高精度的Northern印迹分析。结果表明，1个克隆在轻度矮生豌豆幼苗中特异表达，1个克隆在除轻度矮生豌豆幼苗外的所有幼苗中表达。因此，这两个新基因可能参与了矮生型豌豆植株的光诱导矮化。

In order to clarify the mechanism of light-induced dwarf ism, a search for specific gene involved the dwarfism in dwarf pea plants was undertaken using differential display method. Poly(A)^+ RNA was isolated from light-grown dwarf pea (Pisum sativum L.cv. Progress No 9) and normal pea (cv. Alaska) seedlings and dank-grown seedlings of both cultivars. After reverse transcription of the Poly(A) ^+ RNA, the differential display method was employed to identify specific genes using 72 kinds of random primers. Differentially expressed 20 bands were identified and seven of them were chosen for further characterization. These seven bands were cloned into plasmid vectors and their nucleotide sequences were determined and searched for their homologues in GenBank. Using the cloned coding sequence as probes, the clones were characterized further by Northern blotting at high stringency. The result shown that one clone was specifically expressed in the light-grown dwarf pea seedlings and one was expressed in all seedlings expect the light-grown dwarf pea seedlings. Thus, the two clones, which are novel genes, may be involved in the light-induced dwarfism of the dwarf pea plants.